This invention relates to an electronic monitor system for automobiles and other vehicles, and more particularly to improvement in the monitor system which warns the driver both by flashing light or buzzer sounds and by appropriate indicator light which tells the location if there is something wrong with any one of various functions installed through the car.
Various functions are installed in different locations through the car, and care must be taken to keep the functions operating properly. Those functions include all mechanically or electrically operated points and component parts thereof. It is generally known that the safety driving depends largely on the condition or proper operation of some important functions. Those important functions include those for brake oil, engine oil and battery fluid levels, and various lights, for example.
There is known a centralized monitor system which warns the driver by a flashing light and by an indicator light if something wrong or abnormal occurs with any individual functions located at different points through the car. According to the known monitor system, there are provided sensors which monitor the operation of their respective functions, and a warning element located in the position coming in sight of the driver and actuated by signals from the sensors. If an abnormality is detected by a particular sensor, the sensor will produce an electrical signal which actuates the warning element to flash at regular intervals and also turns on an appropriate indicator light which tells the location so that the driver can be warned of the abnormality and the location.
It may be understood from the foregoing description that the known monitor system has an advantage since it provides centralized warning means which can warn the driver during the normal driving immediately if there is something wrong with any one of the functions located through the car, and can also let the driver know the location. However, it has been noted that the known monitor system has several problems from the practical standpoint. One major problem is that the warning action which is once triggered when a particular function has something wrong or abnormal cannot be cut off in any way. The warning action should not be interrupted as long as the function continues to operate improperly. However, it has become apparent that this continued warning signal may bother the driver who has been warned, and prevent him from driving with safety. Since the driver has been aware of the abnormality in this case, the warning action should preferably be cut off or interrupted. For example, flashing light or buzzer sounds will often place the driver on his nerves while he drives a distance to an appropriate place such as a service station.
There are some major functions that need emergency care or repair, and others that need no such care. It will be practically inconvenient if no means is provided by which the warning action can be released if there is something wrong with any one of the minor functions. Functions such as battery fluid level, windshield washer fluid level and tail lamps, for example, are not considered to be major problems in the event of failure. In such events, the driver will usually drive to a repair or service station. According to the known monitor system, in those cases, the driver must always be bothered by the flashing light or buzzer sounds until he arrives at the service station. If the service station should be located relatively remote, the flashing light or buzzer sounds will continue to annoy the driver during that distance. It will readily be understood that the known monitor system is disadvantageous from the safety standpoint.
The present invention has overcome the above disadvantages from the practical and safety standpoints. The monitor system according to the invention includes control circuit which regulates the strength of warning signals provided by a main warning apparatus. If there is something wrong with any minor function that needs no emergency care, the control circuit determines that it is a minor problem, and then works so that it weakens the strength of the warning signal provided by the warning apparatus without affecting the operation of the warning apparatus. The driver can thus be relieved of the flashing light or buzzer sounds that would otherwise bother him while driving to the service station for repair. The control circuit should be actuated as above, as far as the minor functions are concerned, but desirably should not be so actuated if there is something wrong with major functions such as brake oil level and brake lamp breakage or burn-out which may immediately lead to serious problems.
In order to satisfy those needs, discriminator circuit is provided which determines whether the functions need emergency care or not if an abnormality is detected. More particularly, the discriminator circuit works so that it selectively renders the action of the control circuit valid and invalid depending on the type or importance of the functions. If there should be something wrong with any major function while the strength of the warning signal is maintained to a lower level, the discriminator circuit will then be actuated immediately so that it renders the action of the control circuit invalid and restores the warning signal to its normal strength.